Pathologic changes in the exorbital lacrimal gland of the vitamin A-deficient rat.
Histologic changes in lacrimal glands of vitamin A-deficient (A-) and pair-fed control rats were compared. In A- lacrimal glands, secretory granules were strikingly diminished, and rough endoplasmic reticulum appeared somewhat atrophic. Nuclei of acinar cells were hyperchromatic and pleomorphic. Using alcian blue-PAS, no positive staining was present in acini of A- lacrimal glands, whereas in controls apical portions of acini were intensely stained. Thus, lacrimal tissues of A- rats were thought to be poorly differentiated as a glandular epithelium. When A- rats were supplemented with retinyl acetate, secretory granules reappeared, rough endoplasmic reticulum cisternae greatly dilated, and mitochondria proliferated, indicating accelerated secretory activity. Resupply of vitamin A can induce glandular differentiation in A- lacrimal tissues. Tear volume was not decreased in A- rats compared with pair-fed controls. Regression of secretory organelles in A- lacrimal tissues may lead to a decrease in protein and mucoprotein secretion and subsequent changes in tear composition.
Hayashi
K
K
Eye Research Institute of Retina Foundation, Boston, MA 02114.
Reddy
C
C
Hanninen
L
L
Wolf
G
G
Kenyon
K R
KR
D000818:Animals; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D004848:Epithelium / Q000648:ultrastructure; D007765:Lacrimal Apparatus / Q000648:ultrastructure*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013666:Tears; D014802:Vitamin A Deficiency / Q000473:pathology*